Cellular biological aspects of mammalian peripheral nerve will be studied in order to further understand patterns of dysfunctional states of these tissues. Several different methodologies will be employed including biochemical immunochemical, physiological and various light and electron microscopic morphological techniques. Emphasis will be placed on the concept of calcium ion as mediator of pathological alterations of nerve fibers and attention will be directed towards the changes in axolemmal permeability to calcium ions as a crucial event in the sequence of changes which occur in transected or otherwise devitalized peripheral nerve. Other studies will be directed at the major protein constituents of peripheral nerve, their role in axonal transport phenomena and their possible alterations in dysfunctional states.